Three-dimensional woven fabric

ABSTRACT

1,273,634. Inflated tents. HITCO. 17 July, 1969 [19 Aug., 1968], No. 36158/69. Heading E1A. [Also in Division D1] An inflatable tent is made from joined strips of woven fabric (Division D1) with outer layers 12 joined to inner layers 14 by longitudinal ribs 16, 18 with the outer layers 14 being of greater length than the inner layers 14 so that when inflated, the fabric assumes an arched shape. The fabric may be woven from nylon yarns and the inner and outer layers be sealed by an air-impermeable layer 32.

United States Patent [72] Inventor Walter A. Rheaurne Los Angeles, California [21] Appl. No. 753,390 [22] Filed Aug. 19, 1968 [4S] Patented Nov. 10, 1970 [73] Assignee Hitco a corporation of California [54] THREE-DIMENSIONAL WOVEN FABRIC 9 Claims, 5 Drawing Figs.

[52] US. Cl. 139/384, 139/410 [51] Int. Cl. D03d 3/00, D03d 1 H00 [50] Field of Search 139/384, 384.1,408-413, 20-, 161/90, 91.69

[56] References Cited UNlTED STATES PATENTS Re. 24,007 5/1955 Foster 139/384X 2,046,039 6/1936 Schaar 139/384 2,424,928 7/1947 Glendinning et a1 139/384 1 2,732,865 [/1956 Neisler 139/20 3,009,232 11/1961 Martin 139/384X 3,048,198 8/1962 Koppelman et al... 39/410X 3,090,406 5/1963 Koppelman et al 139/384 3,102,559 9/1963 Koppelman et al 139/384 3,137,604 6/1964 Bosch l61/69X 3,294,605 12/ l 966 Fischer 139/384X FOREIGN PATENTS 47,529 2/1937 France 139/408 I Primary Examiner-James Kee Chi Attorney-Fraser and Bogucki ABSTRACT: A three-dimensional fabric suitable for forming part of a hollow walled structure is woven in the form of longitudinally extending dual-layered fabric having integrally woven longitudinal ribs between the layers. The layers may have different lengths by virtue of different fiber densities in the top and bottom layers or by different total fiber counts in the two layers.

SEALANT MEMBRANE SEALANT llEllBllAliE Pa tented Nov. 10, 1970 Sheet SEALANT MEMBRANE SEALANT NENBRANE FIG.

mvsuron WALTER A. RNEAUNE BY F 'MMMUW ATTORNEYS P atnted Nov. 10, 1970 AIR PRESSURE 'SOUROE INVENTOR mum A. RHEAUME FM Ml ATTORNEYS F l G 5 THREE-DIMENSIONAL WOVEN FABRIC BACKGROUND OF THE IN VENTION 1. Field of the Invention This invention relates to fabric materials and particularly to three-dimensional fabrics useable as air supportable or expandable members.

2. Description of the Prior Art Air-inflated or expanded structures employing fabric walls are being increasingly employed for both large scale structures and relatively small scale components. It is often advantageous in terms of cost and convenience to utilize an inflated construction which is air supported by suitable pressure means. If the inflated structure is formed as an arch only the longitudinal edges need be joined to a supporting structure. The material constituting the structure is formed to have internal conduits which are expanded by the air pressure to cause the assembly to rise and assume the desired shape, after which air flow is needed only to compensate for relatively minor losses. Constructions of this kind generally utilize lightweight fabrics, such as nylon, which have been treated with a sealant material such as synthetic rubber or which have been covered with a coating or adhesively attached film of a material impervious to air.

Several significant practical disadvantages arise in most conventional constructions of this type. The interior conduits are generally defined by webs or ribs that are either sewn or adhesively bonded to outer and inner exterior layers, and it is extremely difficult to obtain the desired uniformity of strength throughout the large number of bonded areas needed for a structure of typical'sizc. Air-inflated structures of this type have been fabricated which are from m 50 feet across and 50 to 100 feet long, and much larger structures are contemplated. A weak point at any of the numerous bonds within the interior structure results in a tear, which immediately induces disproportionate stresses and leads to catastrophic failure virtually immediately after full pressurization. Bonds and seals of this nature are also adversely affected by wear and aging, and the necessary inspection and repair techniques are themselves expensive and time consuming. A need therefore exists for superior three-dimensional fabric constructions having greater strength, reliability and uniformity at comparable cost.

Air-supported units are also widely used in a number of other applications, such as air mattresses, cushions and shock absorbing units. While it is preferable in many instances to have interior webs, constructions of this type are not now predominantly used because of added expense and because they are subject to the same difficulties previously discussed in conjunction with large-scale structures.

SUMMARY OF THE INVENTION Three-dimensional fabrics in accordance with the invention have a selected transverse width and comprise top and bottom fabric layers and at least one integral intermediate fabric rib running longitudinally along the fabric and interwoven into the top and bottom layers. The warp yarns run parallel to the longitudinal axis of the fabric, and fill yarns of the interior ribs are integrally interwoven along selected distances with the top and bottom layers.

Further in accordance with the invention, different layer lengths are used to cause the fabric to have a natural are when expanded. This is preferably provided by the use of different pick counts per inch, while maintaining the same total number of picks relative to a given length along the central plane of the fabric. In another example, differential lengths are provided while using the same pick counts per inch in the two layers.

' BRIEF DESCRIPTION OF THE DRAWINGS A better understanding of the invention may be had by reference to the following description, taken in conjunction with the accompanying drawings, in which:

LII

FIG. 1 is a broken-away perspective view of a fragment of a three-dimensional fabric in accordance with the invention, shown in expanded form;

FIG. 2 is an idealized end sectional view of the three-dimensional fabric of FIG. 1, showing the relationship of the yarns therein;

FIG. 3 is an idealized side sectional viewof a portion of the fabric of F IG. 1, showing the relationship of the yarns in a first type of fabric in accordance with the invention;

FIG. 4 is an idealized side sectional view of a portion of the fabric of FIG. 1, showing the relationship of the yarns in a second type of fabric in accordance with the invention; and

FIG. 5 is a perspective view, partially broken away, of a fragment of an air-supported structure employing fabrics in accordance with the invention.

DETAILED DESCRIPTION OF THE INVENTION In FIG. I, to which reference is now made, there is shown a three-dimensional fabric 10 lying along a longitudinal axis, but rectangularly expanded. Under normal conditions of air expansion, surfaces subject to differential pressure would of course tend tocurve. The fabric 10 is preferably, for air-supported structures, woven of small-diameter fibers having suitable weather-resistant properties, either inherently or by virtue of applied coatings. Nylon and other synthetic fabrics are preferred for these reasons and because of their relatively high strength to weight ratios.

It may be seen that the length of fabric 10 in the open expanded form shown, comprises a top layer 12 or upper broad wall and a bottom layer 14 or lower broad wall, together with interior ribs or webs 16, 13. The terms top, bottom", upper and lower are used for for ease of reference only in the specification and claims and it is to be understood that the relative attitude of the fabric is not of significance. The direction of weaving is along the length of the fabric 10, which therefore has a central longitudinal axis parallel to the selvage. Normally the top and bottom layers 12, 14 and the ribs 16, 18 are woven in flat superimposed relation. The ribs l6, 18 are integrallywoven with at least parts of the top and bottom layers l2, l4 and lie parallel to the longitudinal central axis. In contradistinction to other three-dimenstional fabric constructions such as evidenced in U.S. Pat. Nos. 3,234,972 and 3,090,406, the woven fabric disclosed herein disposes the warp yarns parallel to the longitudinal axis and the selvage, instead of transverse thereto.

Details of the yarn disposition are shown in idealized form in FIG. 2, in which-the top and bottom layers l2, M of the fabric are slightly transversely displaced, with the ribs 16, 18 being angled in a position intermediate that of the flattened product immediately after weaving and the expanded position shown in FIG. 1. FIG. 2 illustrates a cross section transverse to v the longitudinal axis, but for ease of illustration employs different and greatly enlarged scale. In actuality, for most large air-supported structures the width of the top and bottom layers l2, 14 will be substantial (e.g. 4 feet), and the interior ribs 16, 18 will also be proportionally large, (e.g. 2 feet). In a typical example there are approximately 25 ends per inch and 25 picks per inch in the fabric surfaces forming parts of the three-dimensional fabric 10. Thus it will be seen that in FIG. 2 the overall size of the three-dimensional fabric 10 has been greatly reduced and the relative number and density of the warp and fill yarns per inch greatly reduced in order to show the relationships involved. In the given cross section, the fill yarns 20, 20' in the upper layer extend transversely across the length of the layer with respect to the longitudinal axis of the fabric 10. The same is true of the fill yarns 23, 23 in the bottom layer 14. Warp yarns 26 in these layers are disposed substantially parallel to the longitudinal axis.

The ribs l6, 18 have fill yarns 28, 28' and 30, 30 respectively woven about the interspersed rib warp yarns 29, 31, the terminal portions of these fill yarns 28, 30 being woven integrally into parts of each of the top and bottom layers 12, M.

A number of factors determine the length of this interweave, but adequate anchoring to provide an effectively integral structure typically results if there is approximately 1 inch of interwoven segment in a large-size fabric of the type previously mentioned. The length of the interweave part can be increased or reduced as desired. In the present idealized example, only two interwoven picks have been shown for simplicity.

It will also be recognized that the fill yarns 20, 20' and 23, 23 in each layer are woven to form a selvage at each longitudinal end, and do not simply terminate as shown. Further, the terminal portions of the rib fill yarns 28, 30 loop into the succeeding pick in conventional fashion.

The fabric also is distinctive in that differential lengths top and bottom layer lengths are employed. in a preferred form, these differential lengths are such that the top layer 12 is longer than the bottom layer 14 by virtue of a different pick count per inch, with the two layers l2, 14 having the same total number of picks. Consequently, from the bottom layer 14 to the top layer 12, the pick density within the integrally joined ribs 16, 18 varies progressively. With respect to a central plane intersecting the expanded three-dimensional fabric 10 of FIG. 1 at the midheight point, the top layer 12 is longer and the bottom layer 14 is shorter, in this example, than the fabric length along the central plane. The ribs 16, 18 expand progressively in length from the bottom layer 14 to the top layer 12.

For a better understanding of this relationship, reference should be made to FIG. 3, in which a side section of the fabric 10 is shown in idealized form, to illustrate the yarn relation ship and the natural curvature of the fabric. The fill yarns 28 of the rib 16 run longitudinally, but the warp yarns run between the top and bottom layers 12, 14, looping about the longitudinal warp yarns 2.6. However, the loop ends also are interwoven with a selected number of picks in each of the top and bottom layers in directions parallel to the transverse fill yarns 20, 23, which interweaving is not shown in FIG. 3. The density of the bottom layer 14, in picks/inch is greater than that of the top layer 12, while the density of the rib varies progressively between the layers. The two fabric layers do, however, have the same total number of picks.

in the alternative form of FIG. 4, the weaving schedule is arranged to introduce added picks per inch in the top layer 12, thus maintaining like densities in the two layers, while also giving a differential length relationship. When picks are diffcrentially added in this manner, however, the weaving pattern is arranged to skip loops as the rib fill yarns 23 work between,

the top and bottom layers, thus also providing progressively changing rib fabric characteristics through the rib height.

The fabric 10 is rendered air impermeable by the application of sealing membranes 32, 34 on the top ofthe top layer t2 and on the bottom of the bottom layer, as shown generally in FIG. 1. Consequently, when pressurized air is injected into the interior conduits defined by the ribs and walls, the fabric 10 expands to lie curved about a selected radius. As shown in FIG. 5, when adjacent and adjoined fabric arches 36, 37, 38 are expanded in this manner they provide a strong shaperetaining arched structure.

As described in U.S. Pat. Nos. 3,234,972 and 3,090,406 and the patent references therein, fabrics in accordance with the invention may be provided by three-dimensional weaving utilizing standard looms controlled by predetermined patterns in fashion well understood by those skilled in the art. The basic two-rib construction shown in FIGS. 1 and 2 is preferably provided by weaving the individual layers substantially flat, using one individual shuttle for each layer. Lesser or greater numbers of ribs can be provided, but in each such instance it is preferred to use a corresponding number of shuttles.

Although the invention has been described above in terms of a three-dimensional fabric having specific features, it will be appreciated that the invention is not necessarily limited thereto but embraces all forms and variations falling within the scope of the appended claims.

lclaim: l. A three-dimensional fabric having a selected transverse width, said fabric comprising top and bottom fabric layers and at least one integral intermediate fabric rib running longitudinally thercalong and joining said layers, each said fabric rib being independent of the other ribs and the opposite extremities thereof terminating within said layers.

2. The invention as set forth in claim 1 above, wherein the warp yarns of said layers and said intermediate fabric rib run longitudinally and said ribs are interwoven with said layers for selected transverse distances.

3. A three-dimensional fabric suitable for expansion into a curvilinear body and having a selected transverse width, said fabric comprising upper and lower fabric layers, at least one integral intermediate rib running longitudinally therealong, the fill yarns of said at least one rib being interwoven about the warp yarns of the upper and lower layers through a selected transverse dimension and each said rib terminating within each such layer, and the warp yarns in each of the layers lying substantially parallel to the longitudinal axis.

4. A three-dimensional fabric having a selected transverse width, said fabric comprising top and bottom fabric layers each having warp yarns running substantially parallel to the longitudinal axis of the fabric, at least one integral intermediate fabric rib running substantially parallel to the longitudinal axis of the fabric, and having warp yarns running substantially parallel to said longitudinal axis and fill yarns interwoven with the yarns of the top and bottom layers through selected transverse distances along each ofthc top and bottom layers, said at least one rib terminating within each such layer.

5. The invention as set forth in claim 4 above, wherein the lengths of the top and bottom layers of said fabric vary differcntially with respect to the fabric length along a central plane thereof.

6. The invention as set forth in claim 5 above, wherein the top and bottom layers have different pick counts per inch and substantially the same total number of picks for a given length of fabric along the central plane.

7. The invention as set forth in claim 5 above, wherein the top and bottom layers have substantially the same number of picks per inch, and the top layer has a selected greater proportion of total number of picks to the total number of picks in the bottom layer, with respect to a given length of the fabric along the central plane.

8. The invention as set forth in claim 6 above, wherein there are two fabric ribs, each lying on an opposite side of the longitudinal central axis and substantially parallel thereto, and wherein the density of the rib fabrics in picks per inch varies progressively in the direction between the top and bottom layers.

9. The invention as set forth in claim 7 above, wherein loops in the fill yarn of the rib fabrics are selectively dropped relative to the longer layer to vary the effective density of the rib fabrics in the direction between the top and bottom layers. 

